MICROWAVE PROPERTIES OF HIGH-T-C YBA2CU3O7-DELTA MICROSTRIP RESONATORS WITH DIFFERENT SURFACE MORPHOLOGIES AND FINITE THICKNESSES

Microwave properties of YBa2Cu3O7-delta (YBCO) microstrip ring resonat ors with finite thicknesses and different surface morphologies were in vestigated, The unloaded quality factor of a YBCO resonator made of th ick film appeared smaller than that of a different YBCO resonator made of a less thick film, due to the smaller ratio of the film thickness to the penetration depth, The measured penetration depth appeared to i ncrease due to surface roughness, resulting in a decrease of the ratio of film thickness to the penetration depth and an increase of the eff ective surface resistance, A method is introduced to calculate the int rinsic surface resistance of a high-T-c microstrip resonator with fini te thickness, YBa2Cu3O7-delta (YBCO) microstrip ring resonators with t heir thicknesses in the order of the magnetic field penetration depth were prepared from YBCO thin films grown by laser ablation on LaAlO3 a nd their microwave properties were measured at temperatures above the liquid nitrogen temperature and frequencies in 8-12 GHz.